Copper pour slow to generate, slows down UI afterwards

I’m trying to do a pour of my design, which has ~60 components on a 30x45mm square board. This doesn’t seem like an excessively difficult design, but whenever I try to add a pour I get the dreaded “Aw Snap!” page from Chrome.

Attempting the same in Firefox slows down the UI to a crawl whenever I interact with the board in a way that changes the pour (e.g. assigning a pour net). I suspect the algo used to compute the pour is being run in the UI thread. Is there a way to prevent the UI from grinding to a halt if there are pours on the board? Would moving the pour process to a webworker help with this?

I see increasing instances of Aw Snap during repouring as the design becomes more complex. Six layer board, 26x130mm, about 60 components. Small, simple pours redraw instantly, but the larger ground and power planes fail 9 times out of 10. I’m using Chrome.